The invention relates to a tissue culture or cell cultivation container and closure. In the growing of tissue cultures or cells it is customary to use containers provided with an air tight screw cover in order to prevent contamination of the cell material and also to prevent the escape of cells or substrate to the surroundings. However, the use of such air tight screw covers involves various problems. During the autoclaving of such containers, the closure must be in a slightly open position in order to permit the ambient atmosphere of the autoclaving process to reach and sterilize the interior of the container. Further, it is necessary for the closure to be in a slightly open position during the heating phase in order to prevent an undesirable positive pressure within the container, and also during the cooling phase in order to prevent the generation of an undesirable negative pressure. Further, the positioning of the closure in a predetermined slightly opened position, permits a means for an atmospheric exchange during the tissue culture growth process.
Other container-closure assemblies have been provided in the past having means for an intermediate cooperative positioning of the closure with respect to the container; however, they have not been completely satisfactory since the cap or closure and the positioning mechanism did not provide for a stable positive positioning of the closure or cap. For example, U.S. Pat. No. 4,289,248 utilized a pair of detents on opposite sides of the neck of the container or closure, and a detent formed on opposite sides of the closure or container engagable therewith for positioning the closure in a predetermined open position on the container. Since the closures traditionally have a loose fit upon such containers, there is always a problem of the cap or closure flopping or cocking from side-to-side during the positioning of the closure on the container, and accordingly it was possible to completely miss the detents altogether.
U.S. Pat. No. 4,546,085 incorporated the use of a container having a stepped or offset neck portion and a closure having an annular bead for sealing the container. When the bead was moved to a zone adjacent the offset portion, venting of the container was possible, however, no positive positioning mechanism was employed. Again, such design did not necessarily provide a positive and stable cap placement upon the container as obtained in the present invention.